Engineers demonstrated something incredible. Almost any material can be used to create a device that continuously harvests energy from moist air. It’s not a practical out-of-the-box development, but as its creators say, it overcomes some of the limitations of other combines. All necessary materials must be saturated with nanopores less than 100 nanometers in diameter. It’s about one-thousandth the width of a human hair, so that’s easier said than done, but much easier than expected.

According to a team led by engineer Xiaomeng Liu of the University of Massachusetts Amherst, such a material can collect electricity produced by microscopic water droplets in moist air. They sought their discoveries”The overall effect of Air-gen“.

“Air contains a tremendous amount of electricity,” says engineer Jun Yao of UMass Amherst.

“Imagine a cloud that is nothing more than a mass of water droplets. Each of these droplets contains a charge, and under the right conditions the cloud can produce lightning, but we don’t know how to reliably capture electricity. Small predictable and constantly generating electricity for us so we can harvest it. , we created a man-made cloud.”

If Air-gen sounds familiar, it’s because the team has already developed an air energy harvester. However, their previous device was based on protein nanowires grown by a bacterium called Geobacter sulfur reducers.

It seems that bacteria are not needed.

“After opening geobacter We realized that the ability to generate electricity from air—what we called the “air generating effect” at the time—is general: literally, any material can collect electricity from air as long as it has a certain property,” explains Yao.

This property is nanopores and their size depends on the mean free path of water molecules in moist air. This is the distance a water molecule can travel in air before colliding with another water molecule.

The versatile Air-gen device is made of a thin film of material such as cellulose, silk protein or graphene oxide. Water molecules in the air can easily enter the nanopores and move from the top of the film to the bottom, but as they move, they collide with the edges of the pore.

These charge transfers to the material create buildup, and as more water molecules build up on the film, a charge imbalance occurs between the two sides. This creates an effect similar to what we see in lightning-producing clouds: Rising air creates more collisions between water droplets at the top of the cloud, causing an excessive positive charge in higher clouds and an excessive negative charge in clouds. lower ones.

In this case, the charge could potentially be diverted to power smaller devices or stored in some type of battery.

It is currently still in its infancy. The cellulose film the team tested has an output voltage of 260 millivolts per se in the environment, while a cell phone requires an output voltage of about 5 volts. But the thinness of the films means they can be stacked to scale Air-gen devices to make them more practical.

The fact that they can be made of different materials means that the devices can be adapted to the environment in which they will be used, the researchers say.

“The idea is simple, but never explored before, and opens up all sorts of possibilities,” says Yao. “You can imagine combines made from one kind of material for tropical forests and another for drier regions.”

The next step will be to test the devices in different environments and do scaling studies. But the overall impact of Air-gen is real and the possibilities it offers are promising.

“This is very exciting,” Liu says. “We’re opening the door wide to get clean electricity from the air.” Study published Advanced Materials .